子ども人口時計 

JCCC: Web Japanese Clock of Counting Children's Population

FAQ

1. What is this clock?

Recently Japan's new birth of babies has decreased by 100,000 per year. (In 2023, less than 800,000 new babies, in 2024 less than 700,000.)

This clock simulates  the decrease in number of children in Japan.

This clock also estimates the date when the number of children in Japan will be one as a thought experiment.

2. How do you calculate?

Based on the opened data of estimated population by the Statistics Bureau of Japan, I calculated the rate of decrease in the number of children per year and calculated the future number of children in Japan.

3. What is the main finding?

Keeping the current decreasing rate of children (0-14 yo), the number of Japanese children can be only one on 5th,  Janualy,2720.  

4. Why do you make this clock?

I was deeply impressed by the National Debt Clock in Times Square,  New York City and the Doomsday Clock, the power of visualization of the issues. This clock aims to persuade people to understand the importance of rapid Japanese fertility decrease.

5. Is the day of one child is coming ealier?

 In the first estimaton in 2012, the year was later than the year 4000. The last estimation in 2024, it has became ealier as 2720.

see: Transition of the estimated year.

6. Why has Japan's birth rate fallen?

The rapid postwar economic growth led to an increase in the rate of women with higher education and entering the workforce. However, a social environment in which families could balance work and child-rearing has not been created.


7. How does Japan solve the low ferility issues? 

Japan's population structure is characterized by a simultaneous decline in the birth rate and an increase in life expectancy. Therefore, it is necessary to create a system that allocates the extended life expectancy to labor supply in the elderly and gives young people ample time to raise children in return. I call this system as "Child-rearing moratorium."


2025, Jan., 06 How to estimate the Japanese Clock of Counting Children's Population.

Technical note

This clock is made for persuading people to understand the importance of rapid  Japanese fertility decrease in real time bese.

This clock indicate number of children in last year, this year, and indicate the current decreasing number of children every seconds.

Finally as a thought experiment, this clock estimate the date when the number of Japanese Children will  be only one  just mechanically.

I collect the number of children (0-14 years old) in every April using the opened data from the monthly report of estimated population 

by the Statistics Bureau, Ministry of Internal Affairs and Communications. https://www.stat.go.jp/english/data/jinsui/index.html

Based on the two years Number of children  N(t); this year,  and N(t-1); last year.

I obtain the decreasing rate of N as R.        R=N(t)/N(t-1).　(<1.0).    With the assumption that the R is fixed to the future, 

    N(t+1)=N(t)*R.     ....        N(t+n)=N(t)*R^n.   I estimate the year z when N(z)=1.

The latest clock indicates  the day will be the year 2720.

 

2024/07/19　一部表記を修正しました

2024/04/22　2024年版「子ども人口時計」を公表しました

2024/04/08　2024年１月１日時点の臨時子ども人口時計は、こちら。

2023/04/08　子ども人口時計2024年版は2024.04.21以降に掲載の予定です。

2023.04　　毎年恒例の子ども人口時計　2023年５月版を掲示しました。

2022年、令和4年の出生数80万人割れを受けて、臨時に令和5年1月1日時点での子ども人口時計を推計しました。


https://docs.google.com/document/d/1RoUfApzWMS2qBVe-FlqhZPjHodC6ZeOW/

注：子ども人口時計は、子どもの減少という社会現象のイメージを時計という形で「見える化」するための思考実験です。このため、有効数字を無視して計算している部分があります。